672 Mr. Bentham's Account of two new Genera allied to Olacineae. 



Meisner*, and lastly Endlicherf, have all, with much doubt it is true, 

 placed them near Aurantiacece, whilst LindleyJ inserts them, with equal 

 hesitation, among his Pittosporales^. 



The genera usually considered as true Olacinece, are Olax, Linn., (including 

 Spermaxi/rum,ljabi\\., and Fissilia, Commers.,) Heisteria, Linn., Ximenia,hmn., 

 GomphandrajWall., and, as anomalous forms, Opilia, Roxb., (including Groutia, 

 Guillem.,) and Icacina, Adr, Juss. To these I propose to add, besides Apody- 

 les, E. Meyer, Schomburgk's new genus, which I have called Pogopetalum, and 

 Leretia, Vellozo, now first described, also Schoepjia, Schreb., and Cansjera, 

 Lam. I do not advert to the genera of Du Petit Thouars and Blume, usually 

 enumerated at the end of Olacinece, nor to Quilesia of Manuel Blanco, because, 

 until they shall have been more completely or more accurately described, their 

 affinities can only be guessed at ; and Balanites has long since been rejected 

 by Jussieu, though still occasionally added to Olacinece, for no other reason 

 that I can perceive but from its having once been considered as a species of 

 Ximenia. 



The above-named genera consist chiefly of trees or shrubs, occasionally climb- 

 ing, unarmed, or in Ximenia and some species of Olax, bearing axillary spines. 

 The leaves are alternate, exstipulate, simple and entire, neither glandular nor 

 dotted. The inflorescence is terminal only in Icacina and Apodytes, where it 

 is corymbose ; in all the other genera it is axillary ; glomerate in Heisteria ; 

 racemose in Ximenia, Olax, Schcejrfia, Opilia and Cansjera, the flowers being 

 often distichously arranged in the racemes, sometimes irregular and even 

 solitary in the Australian, one East Indian, and one American species of Olax ; 

 cymose in Pogopetalum, Leretia, and in the male individuals of Gomphandra. 

 The bractes at the base of the pedicels are membranous and very small, 

 excepting in Opilia, where they are broad and imbricate before the raceme is 

 fully developed. Bracteolse are present in Schoepfia. 



The flowers are hermaphrodite in most cases, unisexual by abortion in 

 Gomphandra, and occasionally polygamous in Leretia, 



» 



* Plantarum Vascularium Genera, p. 45, Commentarius, p. 33. 



t Genera Plantarum, p. 1041. J Introduction to the Natural System, p. 32. 



§ Since this paper was read, I have received Decaisne's Memoir on the Mistletoe, in which he fully 

 concurs in Brown's views of the close affinity between the Olacinece and Santalaceee 



